Refrigerator controller



Jan. 3, 1933. R. w. DOEG REFRIGERATOR CONTROLLER Filed July 17, 1930 2 Sheets-Sheet INVENTOR RALP W. DOEG A ONY Patented Jan. 3, 1933 UNITED STATES PATENT OFFICE RALPH W. DOEG, OF DETROIT, MICHIGAN, ASSIGNOR TO KELVINATOR CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN REFRIGERATOR CONTROLLER Application filed July 17,

'pecially applicable for employment as a thermostat for controlling the operation of refrigeratin systems.

Some 0 the more important objects of the invention are, to provide an eflicient and economical device for'the making and breaking of an electrical current for energizing an electrical motor operated refrigerating system in order to obtain cyclic operation of the latter; to provide a switch capable of such adjustment that an desired temperature can be maintained within a refrigerator with which it ma be employed, and to provide a rugged switc structure capable of employment with a refrigerating system in such manner as to exert a proper control over the operation of the system without material variation or failure in operation such as is sometimes encountered with devices employed for this purpose.-

In switches heretofore generally employed withrefrigerating systems, it has been customary to provide certain mechanical stops, triggers, etc., for the purpose of maintaining the contacting elements, of the electrical circuit making and breaking device therein employed,-in engagement until the precise instant when it was desired such contacting elements should be separated. These elements of mechanism have always been a great source of trouble, by reason of the practical impossibility of devisin mechanical elements of this character whic will release the contacting elements at exactly the same time under all conditions.

By employing this invention it is not necessary to provide such releasing mechanism in a switch of this character, for the reason that the contacting mechanism is so constructedas to be instantaneously responsive to the prior movement of one of its parts.

For a better understanding, reference may now be had to the accompanying drawin forming a part of this specification, in whic p Figure 1 is a plan view of a switch mechanism, embod ing the invention, in which a portion oft e upper cover for the mecha- 1930. Serial No. 468,687.

nism is broken away in order to give a better view of the parts located therebeneath;

Figure 2 is a cross sectional view of the mechanism illustrated by Figure 1 taken substantially along lines 22 thereof;

Figure 3 is a fragmentary view of the interior of a refrigerator with the-switch mechanism embodying this invention incorporated therein;

' Figure 4 is a fragmentary cross sectional view of the switch mechanism illustrated in Figures 1, 2 and 3 and taken substantially I along the line 44 of Figure 1.

Referring particularly to Figure 3, the interior lining of a refrigerator 10 is rovided with openings for the reception of sses 11 which are supported by a frame of the refrigerator (not shown). These bosses are internally threaded for the rece tion of studs 12, at the lower ends of whic brackets 13 for supporting a brine tank 14, are secured between nuts 16. A plate 17, (see Figures 1 and 3) which provides an upper closure member for a switch casing 18, is provided with notches indicated by the numeral 19 for receiving the bolts 12 when the plate 17 is moved forwardly therebeyond. The plate 17 is secured rigidly against the lower extremities of the bosses 11 by means of nuts 21, While the switch casing 18 is secured to the lower surface of the plate 17 by means of screws 22 projecting through a plurality of openings in the cover and into threaded openings in the upper surface of the casing. The casing 18 preferably is formed of hard rubber, or some other material capable of being molded, and comprises a channel like member having sides 23 and 24 projecting normally from opposite edges of a third side or bottom wall 26.

The open ends of the casing 18 are adapted to be closed by plates 27 and 28 secured thereto by screws 29 thus leaving the plate 17 to cover and close the remaining 0 ening therein. The plate 27 is provided wlt-h a centrally disposed o ening for receiving a threaded ortion 31 of an end closure member 32 for a collapsible bellows 33. A conduit 34, projecting into the interior of the bellows 33 through an opening longitudinally of the m as.

vided w1th a head 36 in which is formed a threaded opening for the reception of an elongated rod or switch actuating member 37 The rod 37 extends a substantial distance within the interior of the bellows 33 asindicated at 38 and the end of the rod is provided with an opening 39 for the reception of an end portion of the conduit 34. The opening 39 is somewhat larger than the end of the conduit 34 in order to permit the equalization of pressure between the conduit and the interior of the bellows. At the same time this structure provides suitable means for retaining the head 36 at the opposite end of the bellows in proper alignment. The opposite extremity of the rod 37 is provided with a reduced portion 390 for slidably engaging an opening in a guide 41 secured rigidly in a centrally disposed opening formed in the end plate 28.

It is apparent that the shoulder formed between the reduced portion 39a and the rod 37 will provide a stop for the purpose of limiting the expansion of the bellows 33.

Before reaching such limit, however, the expansion of the bellows 33 is resiliently opposed by a coil spring 42 surrounding the rod 37 and compressed between the inner extremity of the boss 41 and a flanged washer 43 surrounding the rod. The position of the washer may be varied by adjusting a nut 44, against which the washer abuts, in various longitudinal positions along the rod 37.

The expansion of the bellows 33 is also opposed .by a pair of springs 46 which are secured at opposite ends to the ends of a bifurcated lever 47 and the opposite ends of a bar 48. The bar is provided with a centrally disposed opening through which the threaded rod 37 projects, thus being held rigidly against movement along such rod between the nut 44 and-a nut 51 disposed on the rod 37 on the opposite sideof the nut 44 from the flanged washer 43. v

A fulcrum for the lever 47 is provided by a pin52 projecting into an opening, formed in the wall 24, in parallel relation to the side surface of the latter. The aforesaid wall also is provided with transverse openings in which the bifurcated portions of the lever 47 are. disposed.

The extremity of the lever 47 projecting externally of the casing 18, is provided with an end portion 54 which is adapted to be located selectively in any of a plurality of notches 56 formed in the lower extremity of a flange extension 57 projecting outwardly from the forward edge of the plate 17. Such end of the lever alsohas a suitable handle 58 which projects through an opening in a baflie or closure member 59 positioned in front of the evaporating unit or brine tank 14 and switch inorder to prevent these elements from being seen from the exterior of the refrigerator.

Beyond the nuts 44 and 51 securing the bar 48 in position on the rod 37 and between such elements and the movable end of the bellows 33, is an adjustable toggle supporting member 61 which is threaded on Lhe rod 37 and secured in locked position by a nut 62. The supporting member 61 is provided with a pair of diametrically opposed lugs 63 (see Figure 2) which extend longitudinally of the central axis of the rod. These lugs are each provided with a pair of notches 64disposed in spaced relation, or

each lug but with the notches on corresponding sides of the lugs in alignment. The aligned notches of each pair are adapted to receive sharpened portions at the end of a pair of toggle blades 66 and 67 which project normally relative to the rod 37. Theshurpened ends of each of the toggle members 66 and 67 are cut away as indicated at 68 to provide clearance space for the rod 37 and the toggle supporting member 61.

Lugs 69, having openings for the reception of hooks formed at opposite ends of springs 71, project in opposite directions from the toggle blades 66 and 67, in pairs arranged equally distant from the sharpened ends of the blades. The springs tend to compress the sharpened ends of the blades 66 and 67 into the notches in the lugs 63 and under certain rather than in normal relation to the rod 37.

The toggle blade 67 terminates in a region immediately beyond the lugs 69 and the end thereof projects between a spaced pair of lugs 72 and 73' formed in a bracket 75 secured to the side 24 of the casing 18 by screws 74.

A portion 76 of the blade 66 extends beyond the lugs 69 projecting therefrom and into an opening formed by an offset portion 77 of the wall 23 of the casing 18. On the upper surface of the blade 66, between the recess 68 formed in the sharpened end thereof and the outer extremity of the portion 67, is secured a strip of insulating material 78. Screws 79 are employed for the purpose of securlng the strip of insulating material 78 rigldly to the blade 66. The strip 78 is intersected adjacent the outer extremity thereof relatively staggered, on opposite'surfaces of g Beyond this web is a terminal late 82 which carries, adjacent its outer en a pair said elements are secured on this pin by a cotter pin 85 which permits the compression of the spring 84 but limits the expansion thereof.

When the toggle blade 66 is deflected upwardly towards the bellows 33, the contacting elements 83 are adapted to engage a pair of contacting elements 86 and 87 each of which is connected to a separate terminal of a power line (not shown).

It will be apparent that when these contacting elements are so engaged, it will be possible for an electrical current to flow from the contacting elements 87, for example, through the terminal plate 82 to the contacting element 86. Under such circumstances, in a refrigerating apparatus, the condensing unit thereof will be actuated to produce refrigeration, whereas such function will be discontinued when the aforesaid contacting elements are separated.

Beneath the portion 76 of the blade-66, is an adjusting screw 89 projecting through the wall 23 of the casing 18. The screw may be secured with its end portion in any desired relation to the blade 66 by manipulating the lock nut 91.

The cover plate 17 has secured thereto, b means of rivets 92, a bracket 93 provided wit a pair of elongated openings 94 through which the lower ends of the rivets project.

These openings permit the bracket 93 to slide a limited distance along the lower surface of the cover 17. The opposite ends of the bracket 93 are provided with lugs 95 and 96 between which the toggle blade 66 and an inner extremity of the lever 47 are respectively arranged.

It is apparent that when the lever is rotated in a counterclockwise direction (see Figure 1), its inner end will engage the lug 95, thus moving the bracket 93 within the limits of the opening 94 until the lug 96 engages the blade 66 and separates the contacting elements 83 from the elements 86 and 87.

In the operation of the invention, assuming the bulb at the extremity of the conduit 34 to be located in the interior of the refrigerator, it is apparent that the bellows 33 will be expanded in direct relation to the temperature of the fluid in the bulb. For example, the bellows 33 will be expanded to a greater degree when the temperature in the interior of the refrigerator is high than it will be when such temperature is relatively lower. As the relation of the elements is shown in Figure 1, the bellows 33 has previously been expanded to a relatively great degree, and in its present position is being slightly contracted due to the resistance of the spring 42 and the decreased temperature in the interior of the refrigerator resulting from a relatively long period of operation of the refrigerating system. In otherwords, the switch is ap roaching a condition wherein the refrigeratmg system will be cut out. As the temperature in the refrigerating system continues to decrease, the efl'ect of the spring 42 will be to continue to move the toggle supporting member 61 towards the stationary head 32 of the bellows 33, and eventually such movement will so change the position of the sharpened endsof the toggle members 66 and 67 that the lug 72 will cause the springs 71 to cross the point of contact between the sharpened ends of the toggle member 67 and the toggle supporting member 61. When this event takes place, the springs will exert a compo nent of force against the toggle blade 67 which will move the outer end of the blade away from the lug 72 and into contact with the lug 73. Such movement will move the central portion of the springs 71 to such an extent that they will rapidly cross the point of contact between the toggle member 66 and the toggle supporting member 61. When this secondcrossing of the line of contact occurs, the force of the springs 71 tending to retain the contacting elements 83 in engagement with the elements 87, will be totally released, and in its place will be exerted a substantial force tending to move the outer end portion 76 of the toggle member 66 into engagement with the inner end portion of the screw 89.

This breaking of the electrical circuit through the terminal plate 82 discontinues the operation of the refrigerating system until such time as the pressure in the bellows 33 is sufiiciently increased to move the nod 37 against the force of the spring 42 at which time the springs 71 are again capable of reversing the position of the toggle members 66 and 67.

The range of the switch or thermostat, or, in other words, the position on a temperature scale at which each of the events of the switch will occur, may be varied by varying the compression of the springs 42 as a result of the manipulation of the nuts 44 and 51. Such range also may be independently adjusted from the exterior of the switch by changing the position of the end 54 of the lever 47 in the notches 56. For example, when the lever is so manipulated as to be rotated in a clockwise direction, the increased tension of the springs 46 will be added to the force normally exerted by the spring 42 to oppose the expansion of the bellows 33, thus increasin the range on the temperature scale at whic the switch operational events will occur. This,

in terms of refrigeration, means that the average temperature in a refrigerator will be higher in proportion to the amount the lever.

47 is rotated in a clockwise direction, for the reason that the range of operation of the switch occurs between higher pressure limits,

If it is preferred to maintain a lower average temperature in the refrigerator, the lever 47 is, of course, rotated in a counterclockwise direction, but the switch will be rendered totally inoperative adjacent the limit of movement of the lever 47 in a counterspirit of the invention or from the scope of the appended claims.

I claim:

1. A pressure responsive refrigerator control mechanism comprising a substantially closed casing, snap acting switch mechanism .within said casing, means for controlling the movement of said switch mechanism comprising a member movable 1n response to pressure variatlons, a rod r1g1dly attached to said member, permanently set spring mechanism opposing movement of the pressure responsive member and rod in one direction, additional spring mechanism also opposing movement of the pressure responsive member in the same direction, and means extending.

through and manually operable exteriorly of the casing for varying the effectiveness of the wcond named spring means, both of said spring mechanisms being so constructed and arranged as to oppose movement of the pressure responsive member under all conditions of operation.

2. A pressure responsive refrlgerator con- ..trol mechanismcomprising a substantially closed casing, snap acting switch mechanism within said casing, means for controlling the movement of said switch mechanism comprising a member movable in response to pressure variations, a rod rigidly attached to said member, permanently set spring mechanism opposing movement-of the pressure responslve member and rod in one direction, additional spring mechanism also op posing movement of the pressure responsive member in the same direction, and means extending through and manually operable exteriorly of the casing for varying the efiectlveness of the second named spring means, both of said spring mechanisms being so conaseaeeo structed and arranged as to oppose movement of'the pressure responsive member under all conditions of operation, and means associated with said manually operable means for maintaining the switch means inoperative to close the circuit upon the movement of the manually operable means to a predetermined posit1on.-

3. A pressure responsive refrigerator control means comprising a substantially clo'sed casing, snap acting switch mechanism within said casing, means for controlling the movement of said switch mechanism comprising a member movable in response to pressure variations, a rod rigidly attached to said member, means opposing movement of the pressure responsive mechanism and rod in one direction under all conditions of operation, said means comprising a pair of resilient spring members, one of which is permanently set, and means extending through and manually operable exteriorly of the easing for varying the effectiveness of the other spring member.

4. A pressure responsive refrigerator control means comprising a substantially closed casing, snap acting switch mechanism within said casing, means for controlling the movement of said switch mechanism comprising a member movable in response to pressure variations, a rod rigidly attached to said member, means opposing movement of the pressure responsive mechanism and rod in one drection under all. conditions of operation, said means comprising a pair of resilient spring members, one of which is permanently set, and means extending through and manually operable exteriorly of the casing for varying the effectiveness of the other spring member, said manually operable means including means for maintaining the switch operating mechanism in open position in accordance wIth a predetermined setting of the manually operable means.

In testimony whereof I hereunto aflix my signature.

RALPH DOEG. 

